Fiber optic devices use single or multiple strands of fibers each having an inner circular glass core coated with a circumferential cladding having a different index of refraction. Light is transmitted along the core and totally reflected from the interface between the core and cladding. Such devices can be used as transmission lines for transmitting information bearing light energy. A transmission line can be formed from a single fiber or it can include a plurality of fibers bundled together. Additionally, several transmission lines can be arranged in parallel for the simultaneous transmission of information along each of the separate lines.
Originally, fiber optic systems utilized simplex interconnection systems with single connector plugs terminating single fiber optic cables. In a simplex system, either transmission or reception of information can take place at one time. Consequently, simplex systems are limited in the amount of information that they can transmit and receive during a given period of time.
To increase the amount of information that can be communicated over fiber optic systems, multi-channel systems were developed. Such multi-channel systems include, for example, duplex connector plugs and cables which are capable of simultaneous transmission and reception. Thus, using a duplex system enables information to be transmitted at a much higher rate.
Despite the advantages, multi-channel fiber optic systems are relatively new, and many simplex systems and parts are already in use, for example, ST and SC type connectors. Consequently, simplex parts are readily available and less expensive because there is an existent inventory. Moreover, it would be difficult if not cost prohibitive to retrofit existing simplex systems with dedicated duplex or other multi-channel parts. Consequently, a need exists for an interconnection system which is compatible with both simplex and duplex parts and which permits the interconnection of simplex parts in a duplex configuration to provide duplex data transmission. Several designs have been proposed to address this problem. Typically, they involve an adapter structure which clamps on two individual connector housings to hold the two connectors in a side-by-side relationship forming a duplex connector.
The present invention is directed to providing an improved, more reliable adapter structure or assembly for holding a pair of connectors in a side-by-side relationship and ensuring that the connectors are maintained in a generally parallel relationship and alignment.